Gas burner



June 14, 1932. W, H. FOSTER n 1,862,673

GAS BURNER Filed April 5, 1929 iff 7 2 0 6 g /Z /6 /7 2 A; g

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Patented `une 14, 1932 UNITED STATES PATENT OFFICE WILLIAM H. FOSTER, FYPSILANTI, MICHIGAN, A'SSIGNOR TO THERMAL ENGINEERING CORPORATION, 0FDETROIT, MICHIGAN, A CORPORATION OF MICHIGAN GAS BURNER Application ledApril 5, 1929. Serial No. 352,711.

rIhis invention relates to gas burners for furnaces of various types,and an object of the invention is to provide a burner for the purposestated in which the mixture of gas and air is produced and ignited in abody exteriorly of the furnace and discharged thereinto, provisionheilig made whereby the volume of air in relation to the volume of gasmay be readily varied without disassembling the parts and in conjunctiontherewith the provision of a means for causing cold air to flow aboutthe device adjacent the point of the burning of the gas in order toprevent overheating thereof.

It is further an object of the invention to incorporate these featuresin a comparatively simple and inexpensive structure and thus to reducethe expense of manufacture.

rThese objects and novel features of the invent-ion are hereinafter morefully described and claimed, and the preferred form of construction of agas burner embodying my invention is shown in the accompanylng drawing,in which- Fig. 1 is a horizontal longitudinal section through theburner.

Fig. 2 is a section taken on line 2-2 of Fig. 1.

The burner consists of the hollow body 1 having a chamber 2 into whichair may flow through the conduit 3 which is controlled by a hand valve4. In this chamber 2 is a conduit 6 with which a pipe 7 is connectedwith the inlet end and provided with ahand valve 8.

The conduit 6 extends into the chamber 2 and is there turned at a rightangle and threaded as at 9 to receive the threaded end of the nozzle 10and through this pipe 7 and nozzle 1() the gas is discharged. A packingring 3l is provided between a shoulder on the nozzle and the terminalend of the conduit 6 to prevent leakage of gas at that point. By makingthis nozzle 10 removable, nozzles of various sizes of apertures may beprovided depending upon the volume of the gas that may b-e desired to bedischarged therethrough.

The body 1 has a hollow extension 11 at one side'in which the nozzle 10is located and this portion 11 is threaded to receive a threaded endofan adjusting element 12. This element 12 has a transverse wall 13apertured as at 14 and coned as at 15 correspondingly with coned end 16forming the termlnal of the nozzle and relative to which the conedsurface 15 is spaced to a greater or less extent by the threading of themember 12 toward or from the nozzle 10. This channel which is thusprovided between the frusto-conical surface 15 and frusto-conical end 16of the nozzle forms a passageway for air from the chamber4 2 dischargedinto the chamber 2 under pressure. By varying the position of the part12 longitudinally on the part 11 a greater lor less volume of air may bedischarged around the end of tle nozzle 10. The volume of flow of air ofcourse may also be controlled by the setting of a hand valve 4:. rThevolume of gas to be supplied per unit of time is also controllable bymeans of a hand valve 8. The valves 4; and 8 may be of any desired typesuitable for the purpose.

The forward end 17 of the member 12 is reduced in diameter and lits intoan end of a combustion element 18 and a set screw 19 is provided bymeans of which the element l 12, once it has been adjusted, maybe heldfrom turning to vary the adjustment for the air flow.

The parts 1 and 12 may be formed of brass while the mixing device 18,which is formed with an enlarged chamber 20 for the purpose, ispreferably formed of chrome'nickel steel alloy which is heat resistantin character and does not scale and oxidize by reason of becoming highlyheated. To prevent the part 18 becoming too highly heated andtransferring such heat to the elements 1 and 12, the structure isarranged to provide for a fiow of atmospheric air about the dischargeend of the member 18 which, being adjacent the flame, tends to becomehighly heated.

I have indicated a wall 21 which is to be understood as beingrepresentative of the wall of a furnace and provided with an aperture 28through which the products of combustion pass into the furnace. Ineither case the pre-ignition or combustion chamber 20 v 10 is undernormal pressur in the member 18 is brou ht to such high temperature asto make it neficial to construct the same of a material of high heatresistant quality and provide a means. by which it ma be air coo ed.

This cooling arrangement is provided in the following manner-due to thehigh temperature attained by the gases at the point of combustion Iprovide a longitudinally apertured member 23 of a high heat resistantmaterial such as porcelain or other convenient material and this devicemay be connected to the furnace 4wall in any approved manner or extendedinto the aperture 22 provided in the furnace wall to receive the same asindicated in Fig. 1 and this member 23 may conveniently extend into thefurnace if desired although not so shown. The member 18 extends intothis porcelain member 23, it being provided at the outer end with anenlarged cylindrical recess 24 of approximately the same diameter as theexternal faces of the ribs 25 rovided on the exterior of the forward en26 'of the member 18. Thus, the member 18 is supported at its forwardend by these fins or ribs which serve to position the end 26 axiall -ofthe central opening 27 of the porcelain e ement. It is. to be noted thatthis member 26 is less in diameter than the diameter of the aperture 27and thus there is a -passagewa 28 for air to flow about the forward endo the member 18 as is indicated by the arrows in Fig.` 1. Air is inducedto flow thereinto as stated by reason of the velocity of the products ofcombustion bein discharged through the end 26 of the memer 18.

The recess 24 is of greater length lon tudinally of the porcelain memberthan t e length of the ribs 2 5 and thus this member 18 may be movedinwardly of the orcelain body or outwardl thereofthroug adjustment ofthe mem r 12 whichl is connected with the body 1 which is fixed inposition b reason of connection of the pipes 3 and thereto.

Flow of gas through the pipe 7 and nozzle e o the gas mains while 'theair sup lied through the pipe 3 may be -under hig pressure. By reason ofthe form of the air channel provided between the end of the nozzle andthe frustoconical portion of the element 12, the gas is caused to flowinto the air body and due to the direction of the air flow the gas andair are thoroughly mixed in the chamber 32 and discharged through theaperture 14a .at the inlet end of the chamber 20. The

chamber is the. re-ignition or combustion chamber and t e member 18 inwhich this chamber is provided is formed of chrome nickel steel alloywhich is heat resistant in character ,and the end `of the brass member17 is protected from the high temperature of the combustion chamber bythe inwardlv extending flange 33 which covers the end of the brassmember 17. Practically the entire combustion takes place in the member18 and in the porcelain member 23 so that only the heat or products ofcombustion ass through the wal of the furnace and lnto the furnace fromthis porcelain member.

With a burner constructed in accordance with the present invention, apositive and accurately controlled fiame is possible. This renders theburner particularly adaptable for use in connection with man?! andvaried types .of furnaces wherein eit er a reducing atmosphere or anoxidizing atmosphere is re uired. It is possible to' accurately controlt e products of the burner because of its characteristics wherein thegaseous fuel and air are thoroughly intermixed and ignited in acombustion chamber wherein a localized explosion of the combustiblemixture occurs. By providing 4for this localized explosion theproportionof the air in the mixture when ignited and exploded may beaccurately measured and controlled so that the products of combustionwhich ultimately enter the furnace can be accurately and properlyproportioned to produce either the required excess of carbon monoxide(C0) and hydrogen (H) if a reducing atmosphere is required or to providean excess of air if an oxidizing atmosphere is required.

In practice the gaseous fuel and air, the air bem ,preferably underpressure, are introduce into chamber 32. The amount of air and gaseousfuel are regulated so as to provide a combustible mixture. Chamber 32acts as a primary mixing chamber and inasmuch as t e inlet aperture 14thereof is of smaller diameter, an expansion of the gaseous fuel and airtakes place u on its introduction into chamber 32. Fo lowing theirexpansion the fuel and air are contracted by their passage through theconstricted outlet aperture 14a. The expansion and contraction of thefuel and air produces a turbulent action thereof which results in apartial intermixin of this fuel and air.

The 'fuel ang air in this partially mixed condition are then introducedinto combustion chamber 20 which, by reason of its larger diameter,ermits another expansion of the then partially mixed Acombustiblemixture. The combustible mixture is'thereupon ignited in combustionchamber 20, this ignition causing a localized explosion in thecombustion chamber 20. This explosion crea'tes a further turbulence inthe mixture and produces a pressure in all directions. This explosionand the resulting turbulence causes a further mixingof the fuel and airand by virtue of the construction of the combustion chamber, causes aportion of the gases,

heated to a temperature suiicient to create' further ignition of theincoming mixture,

fn Hmv rearwardly toward the aperture 14a.

This causes the ignition of the incoming mixture wherein the heretoforereferred to action again takes place. The result is a continuity oflocalized explosions in the combustion chamber 20. The expansion due tothe explosion and liberation of the heat units then follows the path ofleast resistance toward the mouth of the burner from whence it isdirected into the furnace.

Theoretically and for all practical purposes the products of the burnercan be controlled within permissible limits to supply exactly theatmosphere desired in the furnace. However, because of the intense heatgenerated by the combustion chamber, it is expedient from the practicalstandpoint to introduce air around the combustion chamber and into thefurnace. This air wipes the outer wall of the combustion chamber andsuiiciently cools the same to make the burner practical. If a com letelyreducing atmosphere is desired in t e furnace, it obviously is necessaryto provide in the products of combustion originating in the burner, anexcess of carbon monoxide and hydrogen to compensate for this extra airsupply which is introduced into the furnace.

From the foregoing description it is evident that the burner consists offew parts, is of simple form and inexpensive in construction requiringbut little machine work in the production thereof.

Having thus brieiiy described my invention, what I claim and desire tosecure by Letters Patent of the United States is- 1. A gas burner forfurnaces comprising a hollow body having an extension on one side opento the interior thereof, a valve controlled' conduit for air discharginginto the body, a conduit for gas extending into the body andterminatingin a threaded end portion, the axis of which coincides with the axis ofthe side extension, a valve controlled gas conduit connected with saidconduit in the body, a nozzle member adapted for threaded relation withthe said threaded end of the conduit in the body, a cap member for saidside extension, the extension and cap being in threaded relationpermitting variation in position thereof longitudinally of theextension, said cap member having a portion of less diameter extendingoutwardly therefrom andv having a transverse wall formed with anaperture, the wall being countersunk to provide a coned recesscoextensive with the aperture, said nozzle having a cone shaped terminalportion' relative to which the coned recess of t e cap member may beadjusted to vary the volume ofiow of air per unit of time, a tubularelement having an end portion fitting over the extension of the .capmember and detachably connected therewith, fins provided on the exteriorsurface of the opposite end of the tubular element, a conduit formed ofrefractory materlal having a central aperture counterbored at its outerend to receive the fins and spacing the inner end of the tubular memberfrom the wall of the refractory element and providing channels for flowof air about the tubular element to the interior of the refractoryelement, said refractory element being connected with the furnace in amanner to allow the products of combustion to pass thereinto.

2. A gas burner for furnaces comprising a chambered body having an inleton one side and an extension open t0 the chamber, an integral conduitextending into the chamber of the body and having a terminal portionpositioned on the axis of the said extension of the body and providingan inlet for gas, a nozzle detachably connected to the said terminalportion of the integral conduit, a cap member for the extension havingan opening therethrough into which the nozzle extends, the openinghaving a shape corresponding to the external shape of the nozzle andbeing adjustable to vary the space between the nozzle and the wall ofthe aperture through which air from the chamber may flow, a tubulardevice providing an extension for the cap connected with the said cap ina manner to permit adjustment. of the cap on the said body and throughwhich the gas and air may pass, a refractory element having a centralaperture from which the products of combustion pass into the fur' nace,said refractory element and the end of the tubular device being soarranged that the end of the tubular device is supported 1n spacedrelation with the wall of the aperture providing for a iow of air aboutthe exterlor of the forward end of the said tubular element for coolingthe same. i

In testimony whereof I sign this spec1cation.

` WILLIAM H. FOSTER.

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